The present invention relates generally to apparatus for cleaning filter elements and is particularly concerned with an apparatus for cleaning the air filters of automobiles and other types of vehicles or industrial engines.
Automobiles and other vehicles and machines having similar engines typically employ folded paper types of air cleaners for filtering dust and other particles from air entering the engine. In ordinary use these filters become clogged with accumulated dust and dirt, and need cleaning or replacement on a regular basis. When the engine is in use under extreme conditions, for example vehicles used in a desert or an otherwise extremely dusty environment, frequent replacement or cleaning of the filters is needed. Since replacement is relatively expensive, it would be advantageous if the folded paper filter could be cleaned effectively to avoid the need for frequent replacement.
In the past, folded paper air filters for engines of various types have often simply been replaced when clogged, involving significant expense, or have been cleaned simply by directing an air hose at the filter element to blow out any loose particles or dust. However, the air blast from a standard high pressure air line is so powerful that it often damages the relatively fragile filter paper, requiring replacement. U.S. Pat. No. 3,733,639 of Timian describes such an arrangement, in which the filter unit is placed in an enclosure and an air hose extends into the enclosure into the center of the filter unit. A revolving air distributer in the form of a tubular element directed towards the filter element is connected to the inner end of the air line. Thus, a powerful blast of air is directed against the inner side of the annular filter element.